Quarter	Percent
1998-04-01	39.8
1998-10-01	38.6
1999-04-01	34.8
1999-10-01	36.1
2000-04-01	31.8
2000-10-01	30.6
2001-04-01	31.1
2001-10-01	32.6
2002-01-01	32.9
2002-04-01	33.9
2002-07-01	34.0
2002-10-01	30.9
2003-01-01	31.5
2003-04-01	32.3
2003-07-01	32.3
2003-10-01	31.6
2004-01-01	31.7
2004-04-01	30.6
2004-07-01	31.3
2004-10-01	34.2
2005-01-01	28.4
2005-04-01	36.3
2005-07-01	31.7
2005-10-01	31.4
2006-01-01	30.6
2006-04-01	35.8
2006-07-01	35.3
2006-10-01	34.2
2007-01-01	33.0
2007-04-01	38.6
2007-07-01	35.1
2007-10-01	36.5
2008-01-01	38.8
2008-04-01	39.3
2008-07-01	37.6
2008-10-01	30.4
2009-01-01	35.6
2009-04-01	33.0
2009-07-01	38.0
2009-10-01	36.9
2010-01-01	37.2
2010-04-01	36.6
2010-07-01	40.4
2010-10-01	34.5
2011-01-01	31.4
2011-04-01	35.0
2011-07-01	33.2
2011-10-01	35.1
2012-01-01	35.8
2012-04-01	37.2
2012-07-01	34.1
2012-10-01	37.2
2013-01-01	33.8
2013-04-01	33.9
2013-07-01	40.0
2013-10-01	36.2
2014-01-01	33.2
2014-04-01	35.2
2014-07-01	35.5
2014-10-01	37.4
2015-01-01	37.9
2015-04-01	36.0
2015-07-01	34.0
2015-10-01	40.6
2016-01-01	37.9
2016-04-01	36.4
2016-07-01	34.2
2016-10-01	35.1
2017-01-01	34.2
2017-04-01	40.7
2017-07-01	38.4
2017-10-01	32.7
2018-01-01	36.8
2018-04-01	36.6